import config from "@/lib/config";
import { EOL } from "node:os";

type SuccessPosted<T = string> = {
  ok: true;
  data: {
    status: "SUCCESS";
    id: T;
    source: "api";
    deduped: boolean;
    post: {
      id: T;
      content: string;
      zone: "normal" | "free";
      created_at: string;
    };
  };
}

const getRealLength = (str: string): number => {
  const segmenter = new Intl.Segmenter("ja", { granularity: "grapheme" });
  return [...segmenter.segment(str)].length;
};

const realSlice = (str: string, limit: number): string => {
  const segmenter = new Intl.Segmenter("ja", { granularity: "grapheme" });
  const segments = [...segmenter.segment(str)];
  return segments.slice(0, limit).map(s => s.segment).join("");
};

export const createPost = async (data: {
  text: string;
  zone?: "normal" | "free";
  replyTarget?: "all" | "followers" | "mutual" | "mentioned" | "none";
  replyid?: string;
  images?: [Blob, string][];
}, title: string) => {
  const excessedMessage = "**👉返信に続きがあります。**";

  const excessedMessageLength = getRealLength(excessedMessage);
  const eolLength = getRealLength(EOL);
  
  let lines = data.text.split(EOL);
  let firstUniqid = "";
  let count = 0;

  const results: SuccessPosted[] = [];

  while (lines.length > 0) {
    count++;
    let currentText = "";
    
    const maxLength = config.post.maxLength;

    const limit = maxLength - (excessedMessageLength + eolLength * 2);

    while (lines.length > 0) {
      const nextLine = lines[0];
      if (nextLine === undefined)
        break;

      const nextLineLength = getRealLength(nextLine);
      if (nextLineLength > limit && currentText === "") {
        const targetLine = lines.shift() || "";
        currentText = realSlice(targetLine, limit);
        lines.unshift(realSlice(targetLine, limit * -1));
        break;
      }

      const potentialText = currentText
        ? currentText + EOL + nextLine
        : nextLine;
      if (getRealLength(potentialText) <= limit) {
        currentText = potentialText;
        lines.shift();
      } else {
        break;
      }
    }

    currentText = currentText.trimEnd();

    if (lines.length > 0) {
      currentText += EOL.repeat(2) + excessedMessage;
    }

    let postedUniqid = "";
    let success = false;

    for (let attempt = 1; attempt <= config.post.maxRetries; attempt++) {
      try {
        const replyid = data.replyid === undefined && firstUniqid !== ""
          ? firstUniqid
          : data.replyid;

        const formData = new FormData();
        formData.append("content", currentText);
        formData.append("zone", data.zone ?? "normal");
        formData.append("reply_restriction", data.replyTarget ?? "all");
        if (replyid) {
          formData.append("reply_to_id", replyid);
        }
        if (data.images) {
          data.images.forEach(img => formData.append("images", img[0], img[1]));
        }

        const req = await fetch(`https://collapse.jp/api/v3/bot/posts`, {
          method: "POST",
          headers: {
            "Authorization": `Bearer ${config.mtweet.token}`,
            "X-Idempotency-Key": String(process.hrtime.bigint()),
          },
          body: formData,
        });

        const res = await req.json();

        if (res.ok) {
          success = true;
          postedUniqid = res.data.id;
          results.push(res);
          break;
        }

        console.warn(`${title}の投稿に失敗しました (試行 ${attempt}/${config.post.maxRetries}):`, `${res.error.message}(${res.error.code})`);
        if (attempt < config.post.maxRetries) {
          const interval = res.error.details?.retry_after
            ? res.error.details.retry_after * 1000
            : config.post.retryInterval;
          console.log(`${interval}ms待機します...`);
          await new Promise(resolve => setTimeout(resolve, interval));
        }
      } catch (err) {
        console.error(err);
      }
    }

    if (!success) {
      console.error(`${title}の全試行が失敗したため、処理を中断します。`);
      break;
    }

    if (firstUniqid === "")
      firstUniqid = postedUniqid;

    console.log(`${title}を投稿(${count}):`, postedUniqid);

    while (lines.length > 0 && lines[0]?.trim() === "") {
      lines.shift();
    }
  }

  return results;
}